With the increasing emphasis on water conservation and particularly the need for its more efficient use in the growing of a wide variety of crops and other plant life, various forms of drip irrigation systems have been utilized. In such systems, water from a common source under pressure is supplied to a plurality of emitters which allow the water to trickle or drip out at a slow rate. Different forms of emitters for such systems have been developed and many utilize an internal tortuous path for the water in order to create friction and reduce pressure. Almost universally in present drip irrigation systems, the emitters are placed on the ground surface and the water drips out and onto the ground from each emitter placed near the plant. This is often inefficient and unsatisfactory particularly where the ambient temperature may be high or where the soil may be hard. In such situations a large amount of water may be lost to evaporation before it can penetrate the soil to an effective depth. Also, prior art emitters failed to provide suitable means for varying or controlling the flow rate of water from the emitters. Such a capability was found to be vital in many instances in order to compensate for pressure variations at the water source; to accommodate different soil conditions around the plants being irrigated; and also to adjust for the varying irrigation needs of different types of plants, trees or crops.